One concern in wind energy turbine is weight of the nacelle. In particular the rotatable parts of the nacelle should have a rather low weight. This is true in particular for modern high power wind energy turbines.
One approach for reducing weight is to reduce the wall thickness of the rotating elements of the nacelle. However, reducing the wall thickness does result in a reduced strength and stiffness of the rotating element. In particular, the hub of the rotor is subjected to forces resulting from wind acting on the rotor blades and forces resulting from loads due to the rotation of the hub. The hub must be stiff enough so that these forces do not cause deformations. In particular within the flanges for mounting the bearings for the rotor blades the hub must be designed rather stiff so that an ovalization can be prevented which in turn would damage the rotor blade bearings and pitch drives.
Accordingly, an object of the present invention is to provide a hub for the rotor of a wind energy turbine which has a relative low weight and is stiff enough in order to withstand the loads which during operation of the wind energy turbine acts on the hub.